We build a plant on the moon, to extract the water that is most likely to be found in the deep crevices on the moon's poles, instead of going there physically, we control machinery from the earth using telepresence, you could drive a bulldozer on the moon very easily from the earth, if the Americans can fly a drone around the earth to kill people, controlled by telepresence. I'm sure we could control a lathe on the moon, a forklift and a moon truck. Power everything from a nuclear reactor, I'm sure a nuclear submarine could be persuaded to donate it's reactor for the purpose.

Once we have the water on the moon, we split it into hydrogen and oxygen. We build a Saturn five type rocket and fire it to the moon, it's payload being a moontug, we land it where the hydrogen and oxygen are being stored in aluminum tanks constructed from the aluminum that can be found on the moon.

Moontug now it's fueled, lifts off from the Moon and heads towards the Earth, at the appropriate time the equivalent of 'Space Ship One' leaves the Earth borne aloft by equivalent of White Knight, the rubber rocket fires and heads towards the vacuum of space, by this time the moontug is getting close to the Earth and decelerates matching velocity with the rubber rocket, hooks on, and accelerates everything to escape velocity, in the safety of the vacuum of space, job done, the door to the universe is open.

The first thing everyone will say is, it is too expensive, no, if every human being gave up cosmetics, if men gave up shaving and put what they would have spent on shaving in a fund and women took what they would have spent on cosmetics and put it in a fund, I'm sure we would have ample funds with which to reach the stars.